Temperature-adaptive gate driver for GaN switch

Abstract

A temperature-adaptive gate driver for a GaN switch includes a gate-to-source voltage adjustment unit and a driver for outputting an on-state gate-to-source voltage to a gate terminal of the switch. The on-state gate-to-source voltage is adjusted based, in part, on temperature of the switch. The amount of adjustment of the on-state gate-to-source voltage with rise in temperature is based, in part, on high-temperature gate-bias reliability data of the switch and is chosen for a favorable trade-off between performance and life-time. The gate-to-source voltage adjustment unit includes a temperature sense element for sensing temperature of the switch and outputs to the driver an output signal based, in part, on temperature. The gate-to-source voltage adjustment unit includes a regulator for receiving a feedback signal based in part, on resistance of the temperature sense element, and for causing a value of the output signal to be responsive to a value of the feedback signal.

What is claimed is: 
     
         1 . A temperature-adaptive gate driver for a GaN switch, comprising:
 a GaN switch disposed on a GaN substrate;   a driver disposed on another substrate for outputting an on-state gate-to-source voltage to a gate terminal of the GaN switch;   a gate-to-source voltage adjustment unit, disposed on the other substrate, for outputting an output signal to the driver,   wherein the gate-to-source voltage adjustment unit includes a temperature sense element for sensing temperature of the GaN switch; and   wherein the on-state gate-to-source voltage is adjustable based, in part, on the temperature of the GaN switch.   
     
     
         2 . The temperature-adaptive gate driver for a GaN switch of  claim 1 , wherein the temperature sense element is located near the GaN switch so that a temperature of the temperature sense element reflects the temperature of the GaN switch. 
     
     
         3 . The temperature-adaptive gate driver for a GaN switch of  claim 1 , wherein the gate-to-source voltage adjustment unit includes a resistor network coupled to the temperature sense element. 
     
     
         4 . The temperature-adaptive gate driver for a GaN switch of  claim 3 , wherein the gate-to-source voltage adjustment unit includes a regulator for receiving a feedback signal from the resistor network, the feedback signal based in part, on resistance of the temperature sense element, and for causing a value of the output signal to be responsive to a value of the feedback signal. 
     
     
         5 . The temperature-adaptive gate driver for a GaN switch of  claim 1 , wherein the output signal outputted by the gate-to-source voltage adjustment unit to the driver is responsive to a temperature of the temperature sense element. 
     
     
         6 . The temperature-adaptive gate driver for a GaN switch of  claim 5 , wherein the output signal that the gate-to-source voltage adjustment unit outputs to the driver is one of: a temperature-dependent voltage and a temperature-dependent current. 
     
     
         7 . The temperature-adaptive gate driver for a GaN switch of  claim 1 , wherein the on-state gate-to-source voltage of the GaN switch rises with a rise in temperature of the GaN switch in a pre-determined fashion. 
     
     
         8 . The temperature-adaptive gate driver for a GaN switch of  claim 7 , wherein an amount of adjustment in the on-state gate-to-source voltage of the GaN switch with rise in temperature is based, in part, on high-temperature gate-bias reliability data of the GaN switch. 
     
     
         9 . The temperature-adaptive gate driver for a GaN switch of  claim 1 , wherein the gate-to-source voltage adjustment unit changes the on-state gate-to-source voltage according to a pre-determined scheme in response to the output signal of the temperature sense element. 
     
     
         10 . The temperature-adaptive gate driver for a GaN switch of  claim 9 , wherein a temperature versus V GS(on)  profile of the gate-to-source voltage adjustment unit is programmable by a user to allow for a trade-off between performance and life-time. 
     
     
         11 . The temperature-adaptive gate driver for a GaN switch of  claim 10 , wherein the temperature versus V GS(on)  profile of the gate-to-source voltage adjustment unit can be varied by a user based on one or both of: amount of load, and package type. 
     
     
         12 . The temperature-adaptive gate driver for a GaN switch of  claim 1 ,
 wherein the driver is a silicon-based driver having a first terminal for receiving a pulse width modulated signal, a second terminal for receiving the output signal from the gate-to-source voltage adjustment unit, a third terminal coupled to ground, and an output terminal coupled to the gate terminal of the GaN switch.   
     
     
         13 . The temperature-adaptive gate driver for a GaN switch of  claim 1 ,
 wherein the driver is a GaN-based driver having first terminal for receiving a pulse width modulated signal, a second terminal for receiving the output signal from the gate-to-source voltage adjustment unit, a third terminal coupled to ground, an output terminal for outputting a lower voltage to the gate-to-source voltage adjustment unit, and an output terminal coupled to the gate terminal of the GaN switch.   
     
     
         14 . The temperature-adaptive gate driver for a GaN switch of  claim 1 , wherein the other substrate is a silicon substrate. 
     
     
         15 . A circuit, comprising:
 a GaN substrate;   a GaN switch disposed on the GaN substrate, the GaN switch including a gate terminal;   a driver disposed on another substrate, the driver for outputting an on-state gate-to-source voltage to the gate terminal; and   a GaN gate-to-source voltage adjustment unit disposed on the other substrate, the GaN gate-to-source voltage adjustment unit for outputting an output signal to the GaN driver, wherein GaN gate-to-source voltage adjustment unit includes a temperature sense element for sensing temperature of the GaN switch,   wherein the on-state gate-to-source voltage is based, in part, on the temperature of the GaN switch.   
     
     
         16 . The circuit of  claim 15 , wherein the temperature sense element comprises an E-mode GaN device coupled to a resistor network. 
     
     
         17 . The circuit of  claim 16 , wherein the GaN gate-to-source voltage adjustment unit includes a GaN regulator for receiving a feedback signal from the resistor network, the feedback signal based in part, on resistance of the temperature sense element, and for causing a value of the output signal to be responsive to a value of the feedback signal. 
     
     
         18 . The circuit of  claim 15 , wherein the other substrate is another GaN substrate. 
     
     
         19 . A microelectronic package, comprising:
 a first GaN substrate in the microelectronic package;   a GaN switch disposed on the first GaN substrate, the GaN switch including a gate terminal;   a second substrate in the microelectronic package;   a driver disposed on the second substrate, the driver for outputting an on-state gate-to-source voltage to the gate terminal, wherein the on-state gate-to-source voltage is based, in part, on temperature of the GaN switch; and   a gate-to-source voltage adjustment unit disposed on the second substrate, the gate-to-source voltage adjustment unit for outputting an output signal to the driver, wherein the gate-to-source voltage adjustment unit includes:   a temperature sense element for sensing temperature of the GaN switch,   a resistor network coupled to the temperature sense element, and   a regulator for receiving a feedback signal from the resistor network, the feedback signal based in part, on resistance of the temperature sense element, and for causing a value of the output signal to be responsive to a value of the feedback signal.